Process for recovery of metallic values from fume precipitate



No Drawing.

Patented Nov. 14;, 1922..

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ARCHIBALD soorr, or HumaoLn'r, ARIZONA, :AssIoNoa To WESTERN ism'rennu'noroan v COMPANY, OF HUMIBOLDT, ARIZONA, A CORPORATION OF DELAWARE, v

rnoonss FOR RECOVERY or mn'rannc 'vAL Es mom To all whom it may concern."

Be it known'that- I, ARCHIBALl) Soo'r'r, a citizen of the United States residing at Humboldt, in the colln'ty of Yavapaiand stantiall Precipitate, of which the following is a spec- State of Arizona, have 'i-iwentedcertain new and useful Improvements in Processes for Recovery of Metallic Values from Fume ification. i

- This invention relates to the recovery of metallic values from fumi jprecipitate obtained by collection by the so-called Cottrell process, or otherwise, from fume containing volatilized-chlorides of various metals, suchv fume being produced by subjecting the ores .tablished nietalluragical practice to convert the metals into and industries.

The material to which my process particularly applies is the. finely divided precipitate composed essentially. of solid particles of'chloride and oxychloride of various metals, as for example, old, silver, copper, lead, zinc, nickel, etc., also certain impuriproducts valuable in the arts I ties transferred mechanicallyfrom the raw material treated. Such a precipitate is in practice usually obtained by-the application of the so'-called Cottrell process for electrostatic precipitation of fumes containing the volatihzed chlorides of the metals mentioned, or other metals. Such precipitate may also be obtained by other methods, as 'for example, bag houses, scrubbers, etc, and,

I therefore, it is not my intention to limit my invention tothe Cottrell precipitate only, nor tovthetreatment of the metals men- Application filed November 4, .1919. Seria1-fio, 8 35,"753.

tioned above. The precipitate ma be mois:

tened,- if desired, or 'mixed with oi or other;

substance, to put it in suitable. form'for.

' transportation or furnace treatment and to prevent excessive dust loss.

I find but certain precipitates contain some ranorrx'raa'n. .i i.

'sulphurin such quantity as-to make it iii-ff:

advisabletotreat them by themethod do scribed in my application of evendate, the; quantity of sulfur present being sufiicient to interfere with completev reduction of the-'60- metal to metallic form, bufiinsuflicient to" form a matte with the metal present; With precipitates of this character, the first step in my present process consists in adding suflicient sulphuror sulphurous material to form a matte with the valuable metals contained in the ores. I then mix the precipi-f tate with a sufficient quantity of calciumoxide, or calcium carbonate, to satisfy the chlorine in the precipitate, and to form a calcium chlorideslag upon fusion of the,

mixture; In place of calcium oxide or carbonate there may be substltuted sodium carbonate or bicarbonata'or potassium carbonate in treatment, with similar result, or gene crally any basic reagent, orreagent-cont'ainlngil base capable of reacting with the me tallic chlorides in the'precipitate togform a chloride of such base may be used The mlxed charge 18 then fed nto a sulta do furnace and heated in a reducing atmosphere until the non-metallicelements are ('(nni i ied with the calcium or other base and slzigg 'd off, and the metallic element or 'elennzpiis are reduced to matte.

1e"i'11atte is then treated in a Bessemer converter. or other similar apparatus, to desulphurize same and produce a bullion 111 the usual manner.

The chemical reactions involved in my process are as follows:

What I claim is:

containing metallic chlorides and also con- The process of treating fume precipitate.

cluce a matte with the valuablemetallic content of the precipitate, which consists in adding thereto sufi'icient sulphur to produce v a matte, with the valuable metals contained in the precipitate and a basic reagent capable of combining with the chlorine of the precipitate and heating the mixture to form a matte containing such metals and a slag containing the chloride of such basic reagent.

In testimony whereof I have hereunto subscribed my name.

ARCHIBALD SCOTT. 

